FIGURE 1.

Cell length, cell number, and root apical meristem size of wild type (Wt) and ick1/2/5/6/7 mutant Arabidopsis plants. (A) Primary root length of the Wt and ick1/2/5/6/7 quintuple mutant at 2–6 days after germination (DAG). Each datum point represents the average of 16–25 seedlings. (B) Relative root length, cortex cell length and cortex cell number of the mature zone of the Wt and ick1/2/5/6/7 mutant plants at 6 DAG (relative ratio = value of mutant/value of Wt). For root length and cell length analyses, 20–22 seedlings were used. For cell length analysis, at least six cells in the mature zone were measured for each root tip. (C) Differential interference contrast (DIC) images showing the cortex cells of the Wt (upper) and ick1/2/5/6/7 quintuple mutant (lower) roots. Two cortex cells of each line are marked in red. (D) Longitudinal view of root tips of 6-day-old Wt and ick1/2/5/6/7 quintuple (right) plants. The root tips were placed on a glass slide, covered with a coverslip, and viewed under a DIC microscope. The cortex cells around the transition zone are marked in red, and black arrowheads indicate the boundary between meristem and elongation zone. (E) Meristem size of Wt and ick1/2/5/6/7 quintuple mutant plants at 2-6 DAG. The root meristem is expressed as the number of cortex cells in a file extending from the quiescent center (QC) to the first elongated cell. The Student’s t-test was used for analyzing the difference between the Wt and mutant [error bar = SE (standard error); ^∗P < 0.05, ^∗∗P < 0.01]. Each datum point represents the average of 16–25 seedlings. Bars = 100 um.